Polymers of carbon monoxide and olefins, such as ethylene, have been known and available for limited quantities for many years. For example, polyketones are disclosed in Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Vol. 12, p. 132, 1967, and in Encyclopedia of Polymeric Science and Technology, 1968, Vol. 9, 397-402. it is known that polyketones may be prepared by contacting CO and ethylene monomers in the presence of a catalyst. High molecular weight polymers of ethylene which contain small quantities of carbon monoxide can be prepared with the aid of Ziegler catalysts. Low molecular weight polymers of carbon monoxide with ethylene and possibly other olefinically unsaturated hydrocarbons in which all monomer units occur distributed at random within the polymer can be prepared with the aid of radical catalysts such as peroxides. A special class of the polymers of carbon monoxide with ethylene is formed by the high molecular weight linear polymers in which the monomer units occur in alternating order and which polymer consist of units with the formula --CO--(C.sub.2 H.sub.4)--. Such polymers can be prepared with the aid of, among others, phosphorus-, arsenic-, antimony-, or cyanogen-containing compounds of palladium, cobalt or nickel as catalysts.
High molecular weight linear alternating polymers of carbon monoxide and ethylene consisting of units of the formula --CO--(C.sub.2 H.sub.4)--, can also be prepared by using catalyst compositions comprising:
(a) a compound of a Group VIII metal selected from the group consisting of palladium, cobalt and nickel,
(b) a non-hydrohalogenic acid having a pKa less than 6, and
(c) a bidentate ligand of the general formula ##STR1## wherein M represents phosphorus, arsenic or antimony, R is a bivalent organic bridging group which contains at least two carbon atoms in the bridge and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represent hydrogen groups.
Application of these catalyst compositions to a monomer mixture which, in addition to carbon monoxide, comprises for example ethylene and one or more alkenically unsaturated hydrocarbons having the general formula C.sub.x H.sub.y leads to the formation of polymers with units of the formula --CO--(C.sub.2 H.sub.4)-- and units of the general formula --CO--(C.sub.x H.sub.y)-- occurring randomly distributed throughout the polymer chains. The structures of the copolymers and `terpolymers` differ only in that in the case of the `terpolymers` a group --(C.sub.x H.sub.y)-- is encountered at random places in the polymer instead of a --(C.sub.2 H.sub.4)-- group.